diff --git a/app/soapbox/components/dropdown_menu.tsx b/app/soapbox/components/dropdown_menu.tsx
index cf4b09b7c..d56a72a01 100644
--- a/app/soapbox/components/dropdown_menu.tsx
+++ b/app/soapbox/components/dropdown_menu.tsx
@@ -249,7 +249,7 @@ export interface IDropdown extends RouteComponentProps {
   ) => void,
   onClose?: (id: number) => void,
   dropdownPlacement?: string,
-  openDropdownId?: number,
+  openDropdownId?: number | null,
   openedViaKeyboard?: boolean,
   text?: string,
   onShiftClick?: React.EventHandler<React.MouseEvent | React.KeyboardEvent>,
diff --git a/app/soapbox/features/admin/moderation_log.tsx b/app/soapbox/features/admin/moderation_log.tsx
index 83163a382..b7a9bce2e 100644
--- a/app/soapbox/features/admin/moderation_log.tsx
+++ b/app/soapbox/features/admin/moderation_log.tsx
@@ -7,8 +7,6 @@ import { useAppDispatch, useAppSelector } from 'soapbox/hooks';
 
 import Column from '../ui/components/column';
 
-import type { Map as ImmutableMap } from 'immutable';
-
 const messages = defineMessages({
   heading: { id: 'column.admin.moderation_log', defaultMessage: 'Moderation Log' },
   emptyMessage: { id: 'admin.moderation_log.empty_message', defaultMessage: 'You have not performed any moderation actions yet. When you do, a history will be shown here.' },
@@ -18,8 +16,10 @@ const ModerationLog = () => {
   const intl = useIntl();
   const dispatch = useAppDispatch();
 
-  const items = useAppSelector((state) => state.admin_log.get('index').map((i: number) => state.admin_log.getIn(['items', String(i)]))) as ImmutableMap<string, any>;
-  const hasMore = useAppSelector((state) => state.admin_log.get('total', 0) - state.admin_log.get('index').count() > 0);
+  const items = useAppSelector((state) => {
+    return state.admin_log.index.map((i) => state.admin_log.items.get(String(i)));
+  });
+  const hasMore = useAppSelector((state) => state.admin_log.total - state.admin_log.index.count() > 0);
 
   const [isLoading, setIsLoading] = useState(true);
   const [lastPage, setLastPage] = useState(0);
@@ -56,12 +56,12 @@ const ModerationLog = () => {
         hasMore={hasMore}
         onLoadMore={handleLoadMore}
       >
-        {items.map((item, i) => (
-          <div className='logentry' key={i}>
-            <div className='logentry__message'>{item.get('message')}</div>
+        {items.map((item) => item && (
+          <div className='logentry' key={item.id}>
+            <div className='logentry__message'>{item.message}</div>
             <div className='logentry__timestamp'>
               <FormattedDate
-                value={new Date(item.get('time') * 1000)}
+                value={new Date(item.time * 1000)}
                 hour12={false}
                 year='numeric'
                 month='short'
diff --git a/app/soapbox/features/bookmarks/index.tsx b/app/soapbox/features/bookmarks/index.tsx
index 0b1255f32..343d7ffc6 100644
--- a/app/soapbox/features/bookmarks/index.tsx
+++ b/app/soapbox/features/bookmarks/index.tsx
@@ -20,9 +20,9 @@ const Bookmarks: React.FC = () => {
   const dispatch = useAppDispatch();
   const intl = useIntl();
 
-  const statusIds = useAppSelector((state) => state.status_lists.getIn(['bookmarks', 'items']));
-  const isLoading = useAppSelector((state) => state.status_lists.getIn(['bookmarks', 'isLoading'], true));
-  const hasMore = useAppSelector((state) => !!state.status_lists.getIn(['bookmarks', 'next']));
+  const statusIds = useAppSelector((state) => state.status_lists.get('bookmarks')!.items);
+  const isLoading = useAppSelector((state) => state.status_lists.get('bookmarks')!.isLoading);
+  const hasMore = useAppSelector((state) => !!state.status_lists.get('bookmarks')!.next);
 
   React.useEffect(() => {
     dispatch(fetchBookmarkedStatuses());
@@ -43,7 +43,7 @@ const Bookmarks: React.FC = () => {
         statusIds={statusIds}
         scrollKey='bookmarked_statuses'
         hasMore={hasMore}
-        isLoading={isLoading}
+        isLoading={typeof isLoading === 'boolean' ? isLoading : true}
         onLoadMore={() => handleLoadMore(dispatch)}
         onRefresh={handleRefresh}
         emptyMessage={emptyMessage}
diff --git a/app/soapbox/features/favourited_statuses/index.js b/app/soapbox/features/favourited_statuses/index.js
index 73ad5a255..0de3d520d 100644
--- a/app/soapbox/features/favourited_statuses/index.js
+++ b/app/soapbox/features/favourited_statuses/index.js
@@ -32,9 +32,9 @@ const mapStateToProps = (state, { params }) => {
   if (isMyAccount) {
     return {
       isMyAccount,
-      statusIds: state.getIn(['status_lists', 'favourites', 'items']),
-      isLoading: state.getIn(['status_lists', 'favourites', 'isLoading'], true),
-      hasMore: !!state.getIn(['status_lists', 'favourites', 'next']),
+      statusIds: state.status_lists.get('favourites').items,
+      isLoading: state.status_lists.get('favourites').isLoading,
+      hasMore: !!state.status_lists.get('favourites').next,
     };
   }
 
@@ -57,9 +57,9 @@ const mapStateToProps = (state, { params }) => {
     unavailable,
     username,
     isAccount: !!state.getIn(['accounts', accountId]),
-    statusIds: state.getIn(['status_lists', `favourites:${accountId}`, 'items'], []),
-    isLoading: state.getIn(['status_lists', `favourites:${accountId}`, 'isLoading'], true),
-    hasMore: !!state.getIn(['status_lists', `favourites:${accountId}`, 'next']),
+    statusIds: state.status_lists.get(`favourites:${accountId}`)?.items || [],
+    isLoading: state.status_lists.get(`favourites:${accountId}`)?.isLoading,
+    hasMore: !!state.status_lists.get(`favourites:${accountId}`)?.next,
   };
 };
 
@@ -147,7 +147,7 @@ class Favourites extends ImmutablePureComponent {
           statusIds={statusIds}
           scrollKey='favourited_statuses'
           hasMore={hasMore}
-          isLoading={isLoading}
+          isLoading={typeof isLoading === 'boolean' ? isLoading : true}
           onLoadMore={this.handleLoadMore}
           emptyMessage={emptyMessage}
         />
diff --git a/app/soapbox/features/follow_recommendations/components/follow_recommendations_list.tsx b/app/soapbox/features/follow_recommendations/components/follow_recommendations_list.tsx
index 841f5e7d0..e9e295d58 100644
--- a/app/soapbox/features/follow_recommendations/components/follow_recommendations_list.tsx
+++ b/app/soapbox/features/follow_recommendations/components/follow_recommendations_list.tsx
@@ -11,8 +11,8 @@ import Account from './account';
 const FollowRecommendationsList: React.FC = () => {
   const dispatch = useDispatch();
 
-  const suggestions = useAppSelector((state) => state.suggestions.get('items'));
-  const isLoading = useAppSelector((state) => state.suggestions.get('isLoading'));
+  const suggestions = useAppSelector((state) => state.suggestions.items);
+  const isLoading = useAppSelector((state) => state.suggestions.isLoading);
 
   useEffect(() => {
     if (suggestions.size === 0) {
@@ -30,8 +30,8 @@ const FollowRecommendationsList: React.FC = () => {
 
   return (
     <div className='column-list'>
-      {suggestions.size > 0 ? suggestions.map((suggestion: { account: string }, idx: number) => (
-        <Account key={idx} id={suggestion.account} />
+      {suggestions.size > 0 ? suggestions.map((suggestion) => (
+        <Account key={suggestion.account} id={suggestion.account} />
       )) : (
         <div className='column-list__empty-message'>
           <FormattedMessage id='empty_column.follow_recommendations' defaultMessage='Looks like no suggestions could be generated for you. You can try using search to look for people you might know or explore trending hashtags.' />
diff --git a/app/soapbox/features/onboarding/steps/suggested-accounts-step.tsx b/app/soapbox/features/onboarding/steps/suggested-accounts-step.tsx
index 2ef5ab828..0b09ca4c1 100644
--- a/app/soapbox/features/onboarding/steps/suggested-accounts-step.tsx
+++ b/app/soapbox/features/onboarding/steps/suggested-accounts-step.tsx
@@ -1,4 +1,3 @@
-import { Map as ImmutableMap } from 'immutable';
 import debounce from 'lodash/debounce';
 import * as React from 'react';
 import { FormattedMessage } from 'react-intl';
@@ -13,9 +12,9 @@ import { useAppSelector } from 'soapbox/hooks';
 const SuggestedAccountsStep = ({ onNext }: { onNext: () => void }) => {
   const dispatch = useDispatch();
 
-  const suggestions = useAppSelector((state) => state.suggestions.get('items'));
-  const hasMore = useAppSelector((state) => !!state.suggestions.get('next'));
-  const isLoading = useAppSelector((state) => state.suggestions.get('isLoading'));
+  const suggestions = useAppSelector((state) => state.suggestions.items);
+  const hasMore = useAppSelector((state) => !!state.suggestions.next);
+  const isLoading = useAppSelector((state) => state.suggestions.isLoading);
 
   const handleLoadMore = debounce(() => {
     if (isLoading) {
@@ -40,11 +39,11 @@ const SuggestedAccountsStep = ({ onNext }: { onNext: () => void }) => {
           useWindowScroll={false}
           style={{ height: 320 }}
         >
-          {suggestions.map((suggestion: ImmutableMap<string, any>) => (
-            <div key={suggestion.get('account')} className='py-2'>
+          {suggestions.map((suggestion) => (
+            <div key={suggestion.account} className='py-2'>
               <AccountContainer
                 // @ts-ignore: TS thinks `id` is passed to <Account>, but it isn't
-                id={suggestion.get('account')}
+                id={suggestion.account}
                 showProfileHoverCard={false}
               />
             </div>
diff --git a/app/soapbox/features/pinned_statuses/index.js b/app/soapbox/features/pinned_statuses/index.js
index b6649a01b..9901131ba 100644
--- a/app/soapbox/features/pinned_statuses/index.js
+++ b/app/soapbox/features/pinned_statuses/index.js
@@ -21,8 +21,8 @@ const mapStateToProps = (state, { params }) => {
   const meUsername = state.getIn(['accounts', me, 'username'], '');
   return {
     isMyAccount: (username.toLowerCase() === meUsername.toLowerCase()),
-    statusIds: state.getIn(['status_lists', 'pins', 'items']),
-    hasMore: !!state.getIn(['status_lists', 'pins', 'next']),
+    statusIds: state.status_lists.get('pins').items,
+    hasMore: !!state.status_lists.get('pins').next,
   };
 };
 
diff --git a/app/soapbox/features/scheduled_statuses/index.tsx b/app/soapbox/features/scheduled_statuses/index.tsx
index 006e8894c..148c9c0a4 100644
--- a/app/soapbox/features/scheduled_statuses/index.tsx
+++ b/app/soapbox/features/scheduled_statuses/index.tsx
@@ -22,9 +22,9 @@ const ScheduledStatuses = () => {
   const intl = useIntl();
   const dispatch = useAppDispatch();
 
-  const statusIds = useAppSelector((state) => state.status_lists.getIn(['scheduled_statuses', 'items']));
-  const isLoading = useAppSelector((state) => state.status_lists.getIn(['scheduled_statuses', 'isLoading']));
-  const hasMore = useAppSelector((state) => !!state.status_lists.getIn(['scheduled_statuses', 'next']));
+  const statusIds = useAppSelector((state) => state.status_lists.get('scheduled_statuses')!.items);
+  const isLoading = useAppSelector((state) => state.status_lists.get('scheduled_statuses')!.isLoading);
+  const hasMore = useAppSelector((state) => !!state.status_lists.get('scheduled_statuses')!.next);
 
   useEffect(() => {
     dispatch(fetchScheduledStatuses());
@@ -37,7 +37,7 @@ const ScheduledStatuses = () => {
       <ScrollableList
         scrollKey='scheduled_statuses'
         hasMore={hasMore}
-        isLoading={isLoading}
+        isLoading={typeof isLoading === 'boolean' ? isLoading : true}
         onLoadMore={() => handleLoadMore(dispatch)}
         emptyMessage={emptyMessage}
       >
diff --git a/app/soapbox/features/ui/components/__tests__/who-to-follow-panel.test.tsx b/app/soapbox/features/ui/components/__tests__/who-to-follow-panel.test.tsx
index 92123eb24..56e4f8422 100644
--- a/app/soapbox/features/ui/components/__tests__/who-to-follow-panel.test.tsx
+++ b/app/soapbox/features/ui/components/__tests__/who-to-follow-panel.test.tsx
@@ -1,4 +1,4 @@
-import { Map as ImmutableMap, fromJS } from 'immutable';
+import { Map as ImmutableMap, OrderedSet as ImmutableOrderedSet } from 'immutable';
 import React from 'react';
 
 import { render, screen } from '../../../../jest/test-helpers';
@@ -16,12 +16,12 @@ describe('<WhoToFollow />', () => {
           avatar: 'test.jpg',
         }),
       }),
-      suggestions: ImmutableMap({
-        items: fromJS([{
+      suggestions: {
+        items: ImmutableOrderedSet([{
           source: 'staff',
           account: '1',
         }]),
-      }),
+      },
     };
 
     render(<WhoToFollowPanel limit={1} />, null, store);
@@ -44,8 +44,8 @@ describe('<WhoToFollow />', () => {
           avatar: 'test.jpg',
         }),
       }),
-      suggestions: ImmutableMap({
-        items: fromJS([
+      suggestions: {
+        items: ImmutableOrderedSet([
           {
             source: 'staff',
             account: '1',
@@ -55,7 +55,7 @@ describe('<WhoToFollow />', () => {
             account: '2',
           },
         ]),
-      }),
+      },
     };
 
     render(<WhoToFollowPanel limit={3} />, null, store);
@@ -78,8 +78,8 @@ describe('<WhoToFollow />', () => {
           avatar: 'test.jpg',
         }),
       }),
-      suggestions: ImmutableMap({
-        items: fromJS([
+      suggestions: {
+        items: ImmutableOrderedSet([
           {
             source: 'staff',
             account: '1',
@@ -89,7 +89,7 @@ describe('<WhoToFollow />', () => {
             account: '2',
           },
         ]),
-      }),
+      },
     };
 
     render(<WhoToFollowPanel limit={1} />, null, store);
@@ -112,9 +112,9 @@ describe('<WhoToFollow />', () => {
           avatar: 'test.jpg',
         }),
       }),
-      suggestions: ImmutableMap({
-        items: fromJS([]),
-      }),
+      suggestions: {
+        items: ImmutableOrderedSet([]),
+      },
     };
 
     render(<WhoToFollowPanel limit={1} />, null, store);
diff --git a/app/soapbox/features/ui/components/who-to-follow-panel.tsx b/app/soapbox/features/ui/components/who-to-follow-panel.tsx
index 8decff7db..fd6089730 100644
--- a/app/soapbox/features/ui/components/who-to-follow-panel.tsx
+++ b/app/soapbox/features/ui/components/who-to-follow-panel.tsx
@@ -1,6 +1,5 @@
-import { Map as ImmutableMap } from 'immutable';
 import * as React from 'react';
-import { FormattedMessage, defineMessages, useIntl } from 'react-intl';
+import { defineMessages, FormattedMessage, useIntl } from 'react-intl';
 import { useDispatch } from 'react-redux';
 
 import { fetchSuggestions, dismissSuggestion } from 'soapbox/actions/suggestions';
@@ -8,6 +7,8 @@ import { Widget } from 'soapbox/components/ui';
 import AccountContainer from 'soapbox/containers/account_container';
 import { useAppSelector } from 'soapbox/hooks';
 
+import type { Account as AccountEntity } from 'soapbox/types/entities';
+
 const messages = defineMessages({
   dismissSuggestion: { id: 'suggestions.dismiss', defaultMessage: 'Dismiss suggestion' },
 });
@@ -20,11 +21,11 @@ const WhoToFollowPanel = ({ limit }: IWhoToFollowPanel) => {
   const dispatch = useDispatch();
   const intl = useIntl();
 
-  const suggestions = useAppSelector((state) => state.suggestions.get('items'));
+  const suggestions = useAppSelector((state) => state.suggestions.items);
   const suggestionsToRender = suggestions.slice(0, limit);
 
-  const handleDismiss = (account: ImmutableMap<string, any>) => {
-    dispatch(dismissSuggestion(account.get('id')));
+  const handleDismiss = (account: AccountEntity) => {
+    dispatch(dismissSuggestion(account.id));
   };
 
   React.useEffect(() => {
@@ -45,11 +46,11 @@ const WhoToFollowPanel = ({ limit }: IWhoToFollowPanel) => {
       title={<FormattedMessage id='who_to_follow.title' defaultMessage='People To Follow' />}
       // onAction={handleAction}
     >
-      {suggestionsToRender.map((suggestion: ImmutableMap<string, any>) => (
+      {suggestionsToRender.map((suggestion) => (
         <AccountContainer
-          key={suggestion.get('account')}
+          key={suggestion.account}
           // @ts-ignore: TS thinks `id` is passed to <Account>, but it isn't
-          id={suggestion.get('account')}
+          id={suggestion.account}
           actionIcon={require('@tabler/icons/icons/x.svg')}
           actionTitle={intl.formatMessage(messages.dismissSuggestion)}
           onActionClick={handleDismiss}
diff --git a/app/soapbox/reducers/__tests__/status_lists-test.js b/app/soapbox/reducers/__tests__/status_lists-test.js
deleted file mode 100644
index e04a24377..000000000
--- a/app/soapbox/reducers/__tests__/status_lists-test.js
+++ /dev/null
@@ -1,30 +0,0 @@
-import { Map as ImmutableMap, OrderedSet as ImmutableOrderedSet } from 'immutable';
-
-import reducer from '../status_lists';
-
-describe('status_lists reducer', () => {
-  it('should return the initial state', () => {
-    expect(reducer(undefined, {})).toEqual(ImmutableMap({
-      favourites: ImmutableMap({
-        next: null,
-        loaded: false,
-        items: ImmutableOrderedSet(),
-      }),
-      bookmarks: ImmutableMap({
-        next: null,
-        loaded: false,
-        items: ImmutableOrderedSet(),
-      }),
-      pins: ImmutableMap({
-        next: null,
-        loaded: false,
-        items: ImmutableOrderedSet(),
-      }),
-      scheduled_statuses: ImmutableMap({
-        next: null,
-        loaded: false,
-        items: ImmutableOrderedSet(),
-      }),
-    }));
-  });
-});
diff --git a/app/soapbox/reducers/__tests__/status_lists.test.ts b/app/soapbox/reducers/__tests__/status_lists.test.ts
new file mode 100644
index 000000000..2333df89a
--- /dev/null
+++ b/app/soapbox/reducers/__tests__/status_lists.test.ts
@@ -0,0 +1,32 @@
+import reducer from '../status_lists';
+
+describe('status_lists reducer', () => {
+  it('should return the initial state', () => {
+    expect(reducer(undefined, {} as any).toJS()).toEqual({
+      favourites: {
+        next: null,
+        loaded: false,
+        isLoading: null,
+        items: [],
+      },
+      bookmarks: {
+        next: null,
+        loaded: false,
+        isLoading: null,
+        items: [],
+      },
+      pins: {
+        next: null,
+        loaded: false,
+        isLoading: null,
+        items: [],
+      },
+      scheduled_statuses: {
+        next: null,
+        loaded: false,
+        isLoading: null,
+        items: [],
+      },
+    });
+  });
+});
diff --git a/app/soapbox/reducers/admin_log.ts b/app/soapbox/reducers/admin_log.ts
index 494592492..fc02a1c5c 100644
--- a/app/soapbox/reducers/admin_log.ts
+++ b/app/soapbox/reducers/admin_log.ts
@@ -2,30 +2,37 @@ import {
   Map as ImmutableMap,
   Record as ImmutableRecord,
   OrderedSet as ImmutableOrderedSet,
-  fromJS,
 } from 'immutable';
 
 import { ADMIN_LOG_FETCH_SUCCESS } from 'soapbox/actions/admin';
 
 import type { AnyAction } from 'redux';
 
+const LogEntryRecord = ImmutableRecord({
+  data: ImmutableMap<string, any>(),
+  id: 0,
+  message: '',
+  time: 0,
+});
+
 const ReducerRecord = ImmutableRecord({
-  items: ImmutableMap(),
-  index: ImmutableOrderedSet(),
+  items: ImmutableMap<string, LogEntry>(),
+  index: ImmutableOrderedSet<number>(),
   total: 0,
 });
 
+type LogEntry = ReturnType<typeof LogEntryRecord>;
 type State = ReturnType<typeof ReducerRecord>;
 type APIEntity = Record<string, any>;
 type APIEntities = Array<APIEntity>;
 
 const parseItems = (items: APIEntities) => {
   const ids: Array<number> = [];
-  const map: Record<number, any> = {};
+  const map: Record<string, LogEntry> = {};
 
   items.forEach(item => {
     ids.push(item.id);
-    map[item.id] = item;
+    map[item.id] = LogEntryRecord(item);
   });
 
   return { ids: ids, map: map };
@@ -36,7 +43,7 @@ const importItems = (state: State, items: APIEntities, total: number) => {
 
   return state.withMutations(state => {
     state.update('index', v => v.union(ids));
-    state.update('items', v => v.merge(fromJS(map)));
+    state.update('items', v => v.merge(map));
     state.set('total', total);
   });
 };
diff --git a/app/soapbox/reducers/dropdown_menu.ts b/app/soapbox/reducers/dropdown_menu.ts
index 6c36ab8b2..2b5c50252 100644
--- a/app/soapbox/reducers/dropdown_menu.ts
+++ b/app/soapbox/reducers/dropdown_menu.ts
@@ -6,10 +6,11 @@ import {
 } from '../actions/dropdown_menu';
 
 import type { AnyAction } from 'redux';
+import type { DropdownPlacement } from 'soapbox/components/dropdown_menu';
 
 const ReducerRecord = ImmutableRecord({
   openId: null as number | null,
-  placement: null as 'top' | 'bottom' | null,
+  placement: null as any as DropdownPlacement,
   keyboard: false,
 });
 
diff --git a/app/soapbox/reducers/status_lists.js b/app/soapbox/reducers/status_lists.ts
similarity index 73%
rename from app/soapbox/reducers/status_lists.js
rename to app/soapbox/reducers/status_lists.ts
index e07b7078c..be87e2910 100644
--- a/app/soapbox/reducers/status_lists.js
+++ b/app/soapbox/reducers/status_lists.ts
@@ -1,4 +1,8 @@
-import { Map as ImmutableMap, OrderedSet as ImmutableOrderedSet } from 'immutable';
+import {
+  Map as ImmutableMap,
+  OrderedSet as ImmutableOrderedSet,
+  Record as ImmutableRecord,
+} from 'immutable';
 
 import {
   BOOKMARKED_STATUSES_FETCH_REQUEST,
@@ -44,29 +48,38 @@ import {
   SCHEDULED_STATUS_CANCEL_SUCCESS,
 } from '../actions/scheduled_statuses';
 
-const initialMap = ImmutableMap({
-  next: null,
+import type { AnyAction } from 'redux';
+import type { Status as StatusEntity } from 'soapbox/types/entities';
+
+const StatusListRecord = ImmutableRecord({
+  next: null as string | null,
   loaded: false,
-  items: ImmutableOrderedSet(),
+  isLoading: null as boolean | null,
+  items: ImmutableOrderedSet<string>(),
 });
 
-const initialState = ImmutableMap({
-  favourites: initialMap,
-  bookmarks: initialMap,
-  pins: initialMap,
-  scheduled_statuses: initialMap,
+type State = ImmutableMap<string, StatusList>;
+type StatusList = ReturnType<typeof StatusListRecord>;
+type Status = string | StatusEntity;
+type Statuses = Array<string | StatusEntity>;
+
+const initialState: State = ImmutableMap({
+  favourites: StatusListRecord(),
+  bookmarks: StatusListRecord(),
+  pins: StatusListRecord(),
+  scheduled_statuses: StatusListRecord(),
 });
 
-const getStatusId = status => typeof status === 'string' ? status : status.get('id');
+const getStatusId = (status: string | StatusEntity) => typeof status === 'string' ? status : status.id;
 
-const getStatusIds = (statuses = []) => (
-  ImmutableOrderedSet(statuses.map(status => status.id))
+const getStatusIds = (statuses: Statuses = []) => (
+  ImmutableOrderedSet(statuses.map(getStatusId))
 );
 
-const setLoading = (state, listType, loading) => state.setIn([listType, 'isLoading'], loading);
+const setLoading = (state: State, listType: string, loading: boolean) => state.setIn([listType, 'isLoading'], loading);
 
-const normalizeList = (state, listType, statuses, next) => {
-  return state.update(listType, initialMap, listMap => listMap.withMutations(map => {
+const normalizeList = (state: State, listType: string, statuses: Statuses, next: string | null) => {
+  return state.update(listType, StatusListRecord(), listMap => listMap.withMutations(map => {
     map.set('next', next);
     map.set('loaded', true);
     map.set('isLoading', false);
@@ -74,29 +87,29 @@ const normalizeList = (state, listType, statuses, next) => {
   }));
 };
 
-const appendToList = (state, listType, statuses, next) => {
+const appendToList = (state: State, listType: string, statuses: Statuses, next: string | null) => {
   const newIds = getStatusIds(statuses);
 
-  return state.update(listType, initialMap, listMap => listMap.withMutations(map => {
+  return state.update(listType, StatusListRecord(), listMap => listMap.withMutations(map => {
     map.set('next', next);
     map.set('isLoading', false);
-    map.update('items', ImmutableOrderedSet(), items => items.union(newIds));
+    map.update('items', items => items.union(newIds));
   }));
 };
 
-const prependOneToList = (state, listType, status) => {
+const prependOneToList = (state: State, listType: string, status: Status) => {
   const statusId = getStatusId(status);
   return state.updateIn([listType, 'items'], ImmutableOrderedSet(), items => {
-    return ImmutableOrderedSet([statusId]).union(items);
+    return ImmutableOrderedSet([statusId]).union(items as ImmutableOrderedSet<string>);
   });
 };
 
-const removeOneFromList = (state, listType, status) => {
+const removeOneFromList = (state: State, listType: string, status: Status) => {
   const statusId = getStatusId(status);
-  return state.updateIn([listType, 'items'], ImmutableOrderedSet(), items => items.delete(statusId));
+  return state.updateIn([listType, 'items'], ImmutableOrderedSet(), items => (items as ImmutableOrderedSet<string>).delete(statusId));
 };
 
-export default function statusLists(state = initialState, action) {
+export default function statusLists(state = initialState, action: AnyAction) {
   switch (action.type) {
     case FAVOURITED_STATUSES_FETCH_REQUEST:
     case FAVOURITED_STATUSES_EXPAND_REQUEST:
@@ -154,7 +167,7 @@ export default function statusLists(state = initialState, action) {
       return appendToList(state, 'scheduled_statuses', action.statuses, action.next);
     case SCHEDULED_STATUS_CANCEL_REQUEST:
     case SCHEDULED_STATUS_CANCEL_SUCCESS:
-      return removeOneFromList(state, 'scheduled_statuses', action.id || action.status.get('id'));
+      return removeOneFromList(state, 'scheduled_statuses', action.id || action.status.id);
     default:
       return state;
   }